Cable traction device for attachment to energized power cables



Oct. 23, 1962 J. G. THURSTON CABLE TRACTION DEVICE FOR ATTACHMENT TO ENERGIZED POWER CABLES Filed Sept. 2, 1958 2 Sheets-Sheet 1 ea FIG 3 72 JNVENTOR. JAMES G. THURSTON 1962 J. G. THURSTON CABLE TRACTION DEVICE FOR ATTACHMENT TO ENERGIZED POWER CABLES 2 Sheets-Sheet 2v Filed Sept. 2, 1958 FIG INVENTOR. JAMES G. THURSTON United States Patent Ofiice 3,59,955 Patented Oct. 23, 1962 3,059,955 CABLE TRACTION DEVICE FOR ATTACHIVIENT T ENERGIZED POWER CABLES James G. Thurston, 1438 Cliitside Drive, Bellingham, Wash. Filed Sept. 2, 1958, Ser. No. 758,511 4 Claims. (Cl. 294-19) My present invention relates to the general art of traction devices for gripping a power cable so that it may be moved lengthwise, as in taking up the slack or in mending a break in a cable. More particularly, my invention relates to a traction clamp means which may be operated at a point removed several feet from the power cable so as to facilitate the attachment or removal of the clamping member of the traction device through the use of actuating means which can be engaged with the clamp member from a distance and thus facilitate the operation and eliminate any danger of injury when handling energized power cables.

In the erection, repair and servicing of electric conductor power cables it is customary for the line crews to work on these cables while they are energized, especially on repair and maintenance because of the necessity of maintaining a continuity of electric service to the large number of customers who depend upon such services. In the past, it has always been a hazardous operation for the man up on the power line poles, particularly, and in close proximity to the high voltage power lines, and most especially is it hazardous when actual contact is made with these power cables as in applying traction clamping devices thereto for such purposes as taking slack out of the lines or holding the lines while they may be bridged over during the application of special devices in the lines. In order to serve this field, I have provided a specially arranged wire clamping means that can be operated by a shaft-like operating handle, of common use, so that the clamp member can be successfully operated with certainty, dispatch, and with safety from a safe distance.

The principal object of this present invention therefore is to provide a wire gripping device in association with a remotely operated handle so that the clamp means can be attached to or removed from the power lines from a point safely removed from the power cables themselves.

A further object of my invention is to provide a wire gripping clamp means and means adapting it for use with a remote control handle which will be capable of very firm attachment to the clamp means so that the clamp means in turn may be very accurately positioned and then by rotating the handle, the cable clamping means can be effectively operated.

A further object of my invention is to provide a cable clamp means and a handle for operating the same from a remote position so that the clamp means can be applied to or removed from a cable carrying sufficient high voltage current to be lethal in case improper contact was made with it.

A further object of the invention is to provide a lock means and operating means for the lock, 50 simple in construction that it may be adapted to many clamps now existing with a minimum of change in those clamps.

Further objects, advantages and capabilities will be apparent from the description and disclosure in the drawings, or may be comprehended or are inherent in the device.

In the drawings:

FIGURE 1 is a perspective view of a preferred form of cable engaging means and showing the manner in which the remote handle arrangement is secured to the clamp locking means.

FIGURE 2 is a cross-sectional view taken generally along the line 2-2 of FIGURE 1.

FIGURE 3 is a fragmentary view showing the detail of the jaws employed at the end of the remotely operated handle used with my device.

FIGURE 4 is a perspective view looking upwardly, showing the handle connected to the clamping means as it would be arranged during the initial gripping of the cable or in removing the cable engaging means from the cable.

FIGURE 5 illustrates in a perspective view the manner in which my equipment is used.

FIGURE 6 illustrates the principal elements embodied in the remote control handle as used with this present equipment.

Referring more particularly to the disclosure in the drawings, the numerals 1t} and 12 designate the coasting cable gripping jaws. The lower jaw, as iliustrated, is formed as part of, or is fixedly secured to the base plate 14. The upper jaw member 12 is pivo-tably secured at 16 to a lever 18. Lever 18, in turn, is pivotably secured to the trailing end of plate 14 by pivot pin 20 which also passes through the lower jaw member 16. The opposite end of clamp member 12 is provided with an eye bolt means 22, the threaded end 23 of which is guided in a curved slot 24. Slot 24', disposed in the leading end of said base plate, is so formed that when lever 18 is moved in the direction of arrow 26, slot 24 in effect forms a guide and cam which maintains the two jaws 1t] and 12 in parallel relationship during their clamping operation. It is to be noted that both jaws 10 and 12 are grooved as at 30 and 32 so as to more securely grip the wire to which the clamp device is attached.

At its upper end, lever 18 has pivotably secured to it at 34 parallel links as 36 and 38, which are joined at the other end by a bolt 49. Bolt 49 is guided in its movement by the elongated guiding slot 42 formed in base plate 14 so as to insure the parallelism of the two clamp jaws 10 and 12 during the engaging operation. Bolt 40 also normally serves as the shackle pin for the elongated shackle or draft link 44. This link must be of sufiicient length so that it will be possible to include the guide portion 46 of plate 14 and still have adequate space for the engagement of the traction line 48 with its associated thimble 50.

Lever 18 may be provided near its upper end with a trip line not shown, engaging opening 52, for purposes to be more fully explained. Eye bolt 22, in addition to guiding the leading end of jaw 12, has a locking function as will probably be best understood from a study of FIGURE 2. The eye bolt is preferably provided with an integral circular flange 60 and is threaded at its opposite end 23 to operatively engage the threaded opening in jaw 12 and clamping nut 64. The eye bolt passes freely through the cam slot 24 in which it is a guiding fit. Nut 64, which is also threaded onto bolt end 23 is locked, by set screw 67, in an adjusted position to limit the rotation of eye bolt 22 to approximately /4 turn. This arrangement insures just enough clearance at 66 to limit the rotation to the amount required to lock and unlock the clamp. Disposed upon the shank of eye bolt 22 is a spacer element of bushing form 68, which is further provided with a flange of circular form at 70. A washer is preferably provided at 72 to reduce friction as the eye bolt is turned in jaw 12 and applies compressive pressure on the end of jaw 12 by means of the bushing member 68. This application of pressure forms the clamping means whereby jaw 12 is clamped normally in the open position, and against the action of spring 74, which normally tends to close jaws 10' and 12 in the wire or cable to which the traction device is applied.

As an operating means, I provided an elongated handle, permitting the operation of my clamp means at a point sufiiciently far remote from the clamp so as to normally keep the operator well out of any danger of coming in contact with the high tension leads. I prefer to use the conventional hot stick as used by power line service personnel. The stick is preferably provided with a handle normally formed of wood or other dielectric material and is equipped with a ferrule at 82, also preferably of nonconductive material. The shaft proper as 84 is grooved on one side to accept a nonconductive rod as 86. This rod is operatively connected to and serves as the operating means for jaw members 87 and 88. Rod 86 is secured to the slidable handle 90 and is operated thereby. In order to hold the sliding handle 90 in a position to maintain jaws 87 and 88 in a closed position, a locking screw is provided at 92.

Method of Use In using my remote clamping equipment, jaws 10 and 12 are opened wide enough to easily engage the conductor with which it is to be engaged and the jaws are clamped in this open position by means of eye bolt 22 and its associated parts. The remote handle 80 is then secured to the ring 94 of eye bolt 22 by means of jaw members 87 and 88 and then handle 90 is moved to retract the jaw members into sleeve 82, carrying with it the ring portion 94 of the eye bolt, until flange 70 of bushing 63 comes into firm contact with the end surface of sleeve 82. Handle 80 is then locked in position by means of screw 92 and the clamp mechanism of FIGURE 1 is now fixedly positioned on the end of handle 80, after the showing of FIGURES 3, 4 and 5. It is to be noted that bushing 68 has considerable length, and the purpose of this is to insure that flange 70, when abutting the end of sleeve 82, will not interfere with engaging the cable within the grooves 30 and 32 of jaw members 10 and 12 respectively.

FIGURES 4 and 5 show the usual positions for the cable engaging operation. In the engaging operation, bushing 68 with its flange 7t} acts as a guide and stop member, which greatly facilitates the engagement with the power cable as 96. When jaws 1t) and 12 are placed in the proper position on either side of the cable to be secured, shaft 84 is revolved carrying with it of course the ring portion 94 of the eye bolt 22 and thereby releasing the friction locking arrangement of FIGURE 2 so that spring 74 can bring the two jaws 10* and 12 into contact with the cable with sufiicient frictional engagement to insure that when tractive effort is applied to traction line 48 there will be enough resistance to cause the relative movement of pin 40 within slot 42 so as to insure the application of considerable force through links 36 and 38 and lever 18 and effect a very firm engagement of the clamp means with the cable.

When the traction operation has been concluded and it is desired to disengage the clamp means, line 43 is slackened and rod 80 is moved in a direction opposite to the force that had been applied by the traction line so that a reversal of the locking mechanism will be obtained with the separation of jaws 10' and 12. The device can then be lifted otf the wire or, as is often preferable, eye bolt 22 is again tightened so as to maintain the jaws in their open position and thus prevent any interference with the releasing operation by the spring 74.

It is believed that it will be clearly apparent from the above description and the disclosure in the drawings that the invention comprehends a novel construction of a cable traction device for attachment to energized power cables.

Having thus disclosed the invention, I claim:

1. A traction clamp and manuevering means for securing cable traction devices onto energized power cables, comp-rising: a cable tractive device having a base plate and cable gripping jaws, one of which is fixed to said plate and the other a movable jaw pivotably secured thereto and maintained in parallel relationship with said fixed jaw, and which are normally urged into cable gripsac-55 ping relationship; a lever pivotably secured to the adjacent and trailing ends of each of said jaws, ad acent the trailing end of said base plate and disposed to give maximum separation to said ends of the jaws when the lever is substantially at right angles to said fixed jaw; sa1d base plate providing a slot having cam shaped margins in the leading end of said base plate and a coacting bolt passing through the end of the movable jaw, removed from said lever and said base plate, and serving to guide said movable jaw parallel to said fixed jaw as the sa1d lever is revolved; a forwardly extending guide portion of said base having an elongated guiding slot therein; an elongated shackle having a bolt joining its opposite ends and said bolt disposed for movement along said guiding slot disposed longitudinally thereof; link means operatively joining the upper end of said lever and said bolt; resilient spring means secured to said link means and having one end bearing on said lever to bias it to close said jaws initially on a power cable; a traction rope secured to said shackle and adapted to move said jaws into clamping relationship on an electric conductor through the coaction of said shackle, said elongated guiding slot, said link means and said lever; clamping means adapted to secure said movable jaw to said base plate, said clamping means comprising an eye bolt threadedly engaging said movable jaw, passing freely through said base plate cam slot and having an adjustably positioned clamping nut on its outer threaded end and a dielectric shaft having remote controlled gripping means for operatively engaging said clamping means in a rigid manner at right angles to the plane of said base plate, permitting remote maneuvering and operating of said cable traction device.

2. A traction clamp and maneuvering means for securing cable traction devices onto energized power cables, comprising: a cable tractive device having a base plate and coacting cable gripping jaws, one of which is fixed to said plate and the other disposed in movable parallel relationship to the fixed jaw; resilient means for normally urging said jaws into cable gripping relationship; a lever pivotably secured to the adjacent ends of each of said jaws adjacent the trailing end of said base plate and disposed to separate said ends of the jaws to a maximum when the lever is substantially at right angles to said fixed jaw; said base plate having 'a slot in its end removed from said lever the edges of which provide cam surfaces and a coacting bolt passing through the end of the movablejaw, removed from said lever, and through said slot, and serving to guide said movable jaw parallel to said fixed jaw as said lever is revolved toward said slot; an elongated guide portion of said base having a guiding slot therein; an elongated shackle having a bolt joining its opposite ends and said bolt disposed for movement along said guiding slot; link means operatively joining the upper end of said lever and said bolt; a traction rope secured to said shackle and adapt d to move said jaws into clamping relationship on an electric conductor through the coaction of said shackle, said guiding slot, said link means and said lever; screw operated clamping means adapted to secure the movable jaW to said base plate in spaced relationship to the said fixed aw; and means for remotely operatively engaging said clamping means and releasing it so said resilient means may move said jaws into initial clamping engagement with an electric power cable being serviced.

3. A traction clamp and maneuvering means for securing cable traction devices onto energized power cables, comprising, a cable tractive device having a base plate and coacting cable gripping jaws, one of which is fixed to said plate and the other of which is mova'bly secured thereto, said base plate lying in a plane parallel to the path of movement of the movable jaw, a lever having its lower end pivotally secured to adjacent portions of each of said jaws, said base plate remote from sa1d lever being formed to define a cam acting -arcuate slot, bolt means passing through said movable jaw remote from said lever and said slot to guide said movable jaw remote from said lever, said base including an elongated guide portion extending away from said jaws in a direction opposite to said lever, shackle means coasting with said guide portion to follow the same, link means for operatively joining the upper end of said lever and said shackle, and releasable clamping means for pre venting movement of said 'bolt means within said arcuate slot to secure the movable jaw with respect to the fixed aw.

4. A traction clamp as recited in claim 3 in which said clamping means comprises an eye bolt having a threaded end engaged in coacting threads on said movable jaw, stop means secured to the outer end of said eye bolt and bearing on one side of said base plate, a flange adjacent the eye end of said eye bolt and a flanged spacing bushing disposed between said movable jaw and the flange of said eye bolt and means for remotely operating said traction device.

References Cited in the file of this patent UNITED STATES PATENTS 611,297 Volk Sept. 27, 1898 702,334 Schulte June 10, 1902 854,578 Heath May 21, 1907 1,370,651 Johnson Mar. 8, 1921 1,591,525 Gardner July 6, 1926 1,850,186 Stanton Mar. 22, 1932 1,910,937 Thane May 23, 1933 1,942,625 Whalan Jan. 9, 1934 2,095,137 Johnson Oct. 5, 1937 2,191,858 Moore Feb. 27, 1940 2,330,736 Paulson Sept. 28, 1943 

